London Overground Rail Operations was created in 2007.
it is neither in underground or overground. it is a separate system.
Well the easiest way would be to use the London Underground. If it is imperative to use a train there is the London Overground Network. A link to the Underground/Overground rail network can be found below.
There was too much overcrowding in central London to accommodate above ground rail lines into the city.
New Jersey Transit Rail Operations was created in 1983.
Hadley Wood railway station (N.B. managed by First Capital Connect as part of National Rail, not London Overground) is indeed in Transport for London's Fare Zone 6.
The London Underground (or just the underground)
You can use your oyster card the Tube, DLR, London Overground and most National Rail services within London.
none. The nearest thing is the "Luas" in dublin which is an overground tram, that or the national rail service
Provided you have enough pay as you go and/or a valid Travelcard for the zones you can go anywhere you want in zones 1 - 9. It is also valid in all zones on the buses, DLR, Tramlink and London Overground, and on some National Rail routes. http://www.oystercard.bravehost.com/
Yes, from London Paddington station.
The Heathrow Express is an airport rail link that is not officially a part of the National Rail system. It runs from the London Heathrow Airport to the London Paddington station in London.
Réunion Rail was created in 1999.